/*
 * A TypeScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for more info.
 */
/*
 * Configurable variables. You may need to tweak these to be compatible with
 * the server-side, but the defaults work in most cases.
 */
const hexcase: number = 0 /* hex output format. 0 - lowercase; 1 - uppercase        */
const b64pad: string =
     '' /* base-64 pad character. "=" for strict RFC compliance   */
const chrsz: number = 8 /* bits per input character. 8 - ASCII; 16 - Unicode      */

/*
 * These are the functions you'll usually want to call
 * They take string arguments and return either hex or base-64 encoded strings
 */
export function hex_md5(s: string): string {
     return binl2hex(core_md5(str2binl(s), s.length * chrsz))
}

export function b64_md5(s: string): string {
     return binl2b64(core_md5(str2binl(s), s.length * chrsz))
}

export function str_md5(s: string): string {
     return binl2str(core_md5(str2binl(s), s.length * chrsz))
}

export function hex_hmac_md5(key: string, data: string): string {
     return binl2hex(core_hmac_md5(key, data))
}

export function b64_hmac_md5(key: string, data: string): string {
     return binl2b64(core_hmac_md5(key, data))
}

export function str_hmac_md5(key: string, data: string): string {
     return binl2str(core_hmac_md5(key, data))
}

/*
 * Perform a simple self-test to see if the VM is working
 */
export function md5_vm_test(): boolean {
     return hex_md5('abc') === '900150983cd24fb0d6963f7d28e17f72'
}

/*
 * Calculate the MD5 of an array of little-endian words, and a bit length
 */
function core_md5(x: number[], len: number): number[] {
     /* append padding */
     x[len >> 5] |= 0x80 << len % 32
     x[(((len + 64) >>> 9) << 4) + 14] = len

     let a: number = 1732584193
     let b: number = -271733879
     let c: number = -1732584194
     let d: number = 271733878

     for (let i = 0; i < x.length; i += 16) {
          const olda: number = a
          const oldb: number = b
          const oldc: number = c
          const oldd: number = d

          a = md5_ff(a, b, c, d, x[i + 0], 7, -680876936)
          d = md5_ff(d, a, b, c, x[i + 1], 12, -389564586)
          c = md5_ff(c, d, a, b, x[i + 2], 17, 606105819)
          b = md5_ff(b, c, d, a, x[i + 3], 22, -1044525330)
          a = md5_ff(a, b, c, d, x[i + 4], 7, -176418897)
          d = md5_ff(d, a, b, c, x[i + 5], 12, 1200080426)
          c = md5_ff(c, d, a, b, x[i + 6], 17, -1473231341)
          b = md5_ff(b, c, d, a, x[i + 7], 22, -45705983)
          a = md5_ff(a, b, c, d, x[i + 8], 7, 1770035416)
          d = md5_ff(d, a, b, c, x[i + 9], 12, -1958414417)
          c = md5_ff(c, d, a, b, x[i + 10], 17, -42063)
          b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162)
          a = md5_ff(a, b, c, d, x[i + 12], 7, 1804603682)
          d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101)
          c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290)
          b = md5_ff(b, c, d, a, x[i + 15], 22, 1236535329)

          a = md5_gg(a, b, c, d, x[i + 1], 5, -165796510)
          d = md5_gg(d, a, b, c, x[i + 6], 9, -1069501632)
          c = md5_gg(c, d, a, b, x[i + 11], 14, 643717713)
          b = md5_gg(b, c, d, a, x[i + 0], 20, -373897302)
          a = md5_gg(a, b, c, d, x[i + 5], 5, -701558691)
          d = md5_gg(d, a, b, c, x[i + 10], 9, 38016083)
          c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335)
          b = md5_gg(b, c, d, a, x[i + 4], 20, -405537848)
          a = md5_gg(a, b, c, d, x[i + 9], 5, 568446438)
          d = md5_gg(d, a, b, c, x[i + 14], 9, -1019803690)
          c = md5_gg(c, d, a, b, x[i + 3], 14, -187363961)
          b = md5_gg(b, c, d, a, x[i + 8], 20, 1163531501)
          a = md5_gg(a, b, c, d, x[i + 13], 5, -1444681467)
          d = md5_gg(d, a, b, c, x[i + 2], 9, -51403784)
          c = md5_gg(c, d, a, b, x[i + 7], 14, 1735328473)
          b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734)

          a = md5_hh(a, b, c, d, x[i + 5], 4, -378558)
          d = md5_hh(d, a, b, c, x[i + 8], 11, -2022574463)
          c = md5_hh(c, d, a, b, x[i + 11], 16, 1839030562)
          b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556)
          a = md5_hh(a, b, c, d, x[i + 1], 4, -1530992060)
          d = md5_hh(d, a, b, c, x[i + 4], 11, 1272893353)
          c = md5_hh(c, d, a, b, x[i + 7], 16, -155497632)
          b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640)
          a = md5_hh(a, b, c, d, x[i + 13], 4, 681279174)
          d = md5_hh(d, a, b, c, x[i + 0], 11, -358537222)
          c = md5_hh(c, d, a, b, x[i + 3], 16, -722521979)
          b = md5_hh(b, c, d, a, x[i + 6], 23, 76029189)
          a = md5_hh(a, b, c, d, x[i + 9], 4, -640364487)
          d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835)
          c = md5_hh(c, d, a, b, x[i + 15], 16, 530742520)
          b = md5_hh(b, c, d, a, x[i + 2], 23, -995338651)

          a = md5_ii(a, b, c, d, x[i + 0], 6, -198630844)
          d = md5_ii(d, a, b, c, x[i + 7], 10, 1126891415)
          c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905)
          b = md5_ii(b, c, d, a, x[i + 5], 21, -57434055)
          a = md5_ii(a, b, c, d, x[i + 12], 6, 1700485571)
          d = md5_ii(d, a, b, c, x[i + 3], 10, -1894986606)
          c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523)
          b = md5_ii(b, c, d, a, x[i + 1], 21, -2054922799)
          a = md5_ii(a, b, c, d, x[i + 8], 6, 1873313359)
          d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744)
          c = md5_ii(c, d, a, b, x[i + 6], 15, -1560198380)
          b = md5_ii(b, c, d, a, x[i + 13], 21, 1309151649)
          a = md5_ii(a, b, c, d, x[i + 4], 6, -145523070)
          d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379)
          c = md5_ii(c, d, a, b, x[i + 2], 15, 718787259)
          b = md5_ii(b, c, d, a, x[i + 9], 21, -343485551)

          a = safe_add(a, olda)
          b = safe_add(b, oldb)
          c = safe_add(c, oldc)
          d = safe_add(d, oldd)
     }
     return [a, b, c, d]
}

/*
 * These functions implement the four basic operations the algorithm uses.
 */
function md5_cmn(
     q: number,
     a: number,
     b: number,
     x: number,
     s: number,
     t: number,
): number {
     return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)
}

function md5_ff(
     a: number,
     b: number,
     c: number,
     d: number,
     x: number,
     s: number,
     t: number,
): number {
     return md5_cmn((b & c) | (~b & d), a, b, x, s, t)
}

function md5_gg(
     a: number,
     b: number,
     c: number,
     d: number,
     x: number,
     s: number,
     t: number,
): number {
     return md5_cmn((b & d) | (c & ~d), a, b, x, s, t)
}

function md5_hh(
     a: number,
     b: number,
     c: number,
     d: number,
     x: number,
     s: number,
     t: number,
): number {
     return md5_cmn(b ^ c ^ d, a, b, x, s, t)
}

function md5_ii(
     a: number,
     b: number,
     c: number,
     d: number,
     x: number,
     s: number,
     t: number,
): number {
     return md5_cmn(c ^ (b | ~d), a, b, x, s, t)
}

/*
 * Calculate the HMAC-MD5, of a key and some data
 */
function core_hmac_md5(key: string, data: string): number[] {
     let bkey: number[] = str2binl(key)
     if (bkey.length > 16) bkey = core_md5(bkey, key.length * chrsz)

     const ipad: number[] = new Array(16)
     const opad: number[] = new Array(16)

     for (let i = 0; i < 16; i++) {
          ipad[i] = bkey[i] ^ 0x36363636
          opad[i] = bkey[i] ^ 0x5c5c5c5c
     }

     const hash: number[] = core_md5(
          ipad.concat(str2binl(data)),
          512 + data.length * chrsz,
     )
     return core_md5(opad.concat(hash), 512 + 128)
}

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
function safe_add(x: number, y: number): number {
     const lsw: number = (x & 0xffff) + (y & 0xffff)
     const msw: number = (x >> 16) + (y >> 16) + (lsw >> 16)
     return (msw << 16) | (lsw & 0xffff)
}

/*
 * Bitwise rotate a 32-bit number to the left.
 */
function bit_rol(num: number, cnt: number): number {
     return (num << cnt) | (num >>> (32 - cnt))
}

/*
 * Convert a string to an array of little-endian words
 * If chrsz is ASCII, characters >255 have their hi-byte silently ignored.
 */
function str2binl(str: string): number[] {
     const bin: number[] = []
     const mask: number = (1 << chrsz) - 1
     for (let i = 0; i < str.length * chrsz; i += chrsz)
          bin[i >> 5] |= (str.charCodeAt(i / chrsz) & mask) << i % 32
     return bin
}

/*
 * Convert an array of little-endian words to a string
 */
function binl2str(bin: number[]): string {
     let str: string = ''
     const mask: number = (1 << chrsz) - 1
     for (let i = 0; i < bin.length * 32; i += chrsz)
          str += String.fromCharCode((bin[i >> 5] >>> i % 32) & mask)
     return str
}

/*
 * Convert an array of little-endian words to a hex string.
 */
function binl2hex(binarray: number[]): string {
     const hex_tab: string = hexcase ? '0123456789ABCDEF' : '0123456789abcdef'
     let str: string = ''
     for (let i = 0; i < binarray.length * 4; i++) {
          str +=
               hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8 + 4)) & 0xf) +
               hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8)) & 0xf)
     }
     return str
}

/*
 * Convert an array of little-endian words to a base-64 string
 */
function binl2b64(binarray: number[]): string {
     const tab: string =
          'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
     let str: string = ''
     for (let i = 0; i < binarray.length * 4; i += 3) {
          const triplet: number =
               (((binarray[i >> 2] >> (8 * (i % 4))) & 0xff) << 16) |
               (((binarray[(i + 1) >> 2] >> (8 * ((i + 1) % 4))) & 0xff) << 8) |
               ((binarray[(i + 2) >> 2] >> (8 * ((i + 2) % 4))) & 0xff)
          for (let j = 0; j < 4; j++) {
               if (i * 8 + j * 6 > binarray.length * 32) str += b64pad
               else str += tab.charAt((triplet >> (6 * (3 - j))) & 0x3f)
          }
     }
     return str
}
